Introduction
Imaging in Vasculitides
Imaging modality and indication | Technical parameters |
Ultrasound | - Supra-aortic arteries: linear probes - Ascending aorta and aortic arch: sector or convex probes - Abdominal aorta: convex probes - Temporal arteries: B-mode frequency >/= 15 MHz - Extracranial supra-aortic arteries: B-mode frequency for extracranial 7–15 MHz - Temporal arteries: Doppler frequencies 7–12 MHz - Extracranial supra-aortic arteries: Doppler frequencies 4–8 MHz - Angle between sound waves and artery </= 60° - Focus at the level of the artery - Color Doppler preferred over power Doppler mode |
CT | - Multislice CT scanner preferred - Collimation 0,6 mm, tube voltage 120 kV - Tube current time product (mAs) determined by automatic dose modulation - Reconstruction slice thickness 0.5–1.0 mm - Bodyweight adapted injection of 60–120 mL of non-ionic iodinated contrast agent (>/= 350 mg/mL) using a power injector (>/= 4 mL/s) - Arterial phase: bolus tracking method (threshold of 100 HU), ECG triggering - Venous phase: acquisition 50 s after finishing the arterial phase |
MRI | Cranial technique: - 1,5, preferentially 3,0 T MRI scanner, minimum 8 channel head-coil - T1-weighted spin echo, gadolinium contrast-enhanced, fat-suppressed, high-resolution (in plane << 1 mm2, e.g., 195 × 260 μm, slice thickness 3 mm, repetition time (TR)/echo time (TE) 500/22 ms) - T2-weighted turbo spin echo (TSE), non-contrast-enhanced imaging (TR/TE 9000/143 ms) significantly less sensitive - Transversal slices angulated parallel to skull base Body technique: - 1,5, preferentially 3,0 T MRI scanner, minimum 8 channel head and neck coil, 16 channel body coil - MR angiography of aorta and major branches from carotid bifurcation to iliac arteries in coronal acquisition to include axillary and brachial arteries → Detection of vessel lumen (stenosis, occlusion, aneurysm) - T1-weighted, fat-suppressed, contrast-enhanced, black blood imaging (e.g., navigated 3D TSE, spatial resolution 1.2 × 1.3 × 2 mm3, TR/TE 1000/35 ms) → Assessment of mural inflammation - T2-weighted TSE imaging for edema detection in mural inflammation less sensitive and more vulnerable to artifacts |
FDG-PET-CT | - Hybrid PET combined with low-dose CT - Blood glucose levels: preferred < 7 mmol/L (126 mg/dL), < 10 mmol/L (180 mg/dL) acceptable - Interval between FDG infusion and image acquisition at least 60 min, preferably 90 min - Position of patient is supine, position of the arms: arms down - Body part to include from top of head to at least mid-thigh, preferably to below the knees - Scoring FDG uptake, qualitative visual grading; if results unclear, comparison with the liver background (grading 0–3) |
Small Vessel Vasculitides
Medium-Sized Vessel Vasculitides
Large Vessel Vasculitides (LVV) and EULAR Guidelines
Central Nervous System (CNS) Vasculitis
Form of vasculitis | Suitable imaging modality | Evaluable structures/typical imaging findings |
Granulomatosis with polyangiitis (GPA) | CT | Osseous structures (bone erosion, bone regeneration), mucosal swelling, pulmonary changes |
MRI | Mucosal swelling (typically nodular configuration with a hypointense T2-signal) | |
Polyarteritis nodosa | Echocardiography | Heart, heart valves, heart function |
CT/CT-angiography | Complications, bleedings, or necrosis in different organ systems, vessel lesions | |
Catheter angiography | Vessel lesions (stenosis, occlusion, aneurysms) | |
Kawasaki disease | Echocardiography | Heart, heart valves, heart function |
Giant cell arteritis (GCA) | Color-coded duplex sonography (CCDS) | “Halo” sign (non-compressible hypoechoic concentric vessel wall thickening around the superficial temporal artery > 340–420 μm, stenosis, occlusion) |
MRI/MRA | Vessel lesions, particularly of superficial temporal arteries (vessel wall thickening and enhancement, stenosis, occlusion) (intracranial) complications | |
Takayasu’s arteritis (TA) | MRI/MRA | Vessel lesions (vessel wall thickening and enhancement, stenosis, occlusion) intracranial complications |
CT-angiography/FDG-PET-CT | Vessel lesions (vessel wall thickening and enhancement, stenosis, occlusion), disease extent, and activity | |
CNS vasculitis | MRI/MRA | Vessel lesions (vessel wall thickening and enhancement, stenosis, occlusion), intracranial complications |
CT/ CT-angiography | Vessel lesions (vessel wall thickening and enhancement, stenosis, occlusion), intracranial complications | |
Catheter angiography | Vessel lesions (stenosis, occlusion) |